Computers have been networked to exchange data between them for decades. One important network, the Internet, comprises a vast number of computers and computer networks interconnected through communication channels. The Internet is used for various reasons, including electronic commerce, exchanging information such as electronic mail, retrieving information and doing research, and the like. Many standards have been established for exchanging information over the Internet, such as electronic mail, Gopher, and the World Wide Web (“WWW”). The WWW service allows a server computer system (i.e., web server or web site) to send graphical web pages of information to a remote client computer system. The remote client computer system can then display the web pages. Each resource (e.g., computer or web page) of the WWW is uniquely identifiable by a Uniform Resource Locator (“URL”). To view a specific web page, a client computer system specifies the URL for that web page in a request (e.g., a HyperText Transfer Protocol (“HTTP”) request). The request is forwarded to the web server that supports that web page. When that web server receives the request, it sends the requested web page to the client computer system. When the client computer system receives that web page, it typically displays the web page using a browser. A browser is typically a special purpose application program for requesting and displaying web pages.
Currently, web pages are often defined using HyperText Markup Language (“HTML”). HTML provides a standard set of tags that define how a web page is to be displayed. When a user makes a request to the browser to display a web page, the browser sends the request to the server computer system to transfer to the client computer system an HTML document that defines the web page. When the requested HTML document is received by the client computer system, the browser displays the web page as defined by the HTML document. The HTML document contains various tags that control the display of text, graphics, controls, and other features. The HTML document may contain URLs of other web pages available on that server computer system or on other server computer systems.
New protocols exist, such as Extensible Markup Language (“XML”) and Wireless Access Protocol (“WAP”). XML provides greater flexibility over HTML. WAP provides, among other things, the ability to view web pages over handheld, wireless devices, such as cell phones and portable computers (e.g. PDA's). All of these protocols provide easier ways to provide information to people via various data processing devices. Many other protocols and means for exchanging data between data processing device continue to develop to further aid the exchange of information.
In wireless communications, it is common to remedy the problem of media collision by using acknowledged receipt with finite retransmission strategy for point-to-point messages. In order to allow for communication networks of varying density and to ameliorate congestion, it is also common to use delays with an exponentially-increasing coefficient. Broadcast messages, however, may not be able to effectively use acknowledged receipt because the number of recipients is unreliable.
One undesirable characteristic of this strategy is that the most congested and least reliable communication links tend to experience the highest message delivery latency. That latency tends also to increase the probability that another message will be waiting on queue before the completion of the previous message delivery. The combination of these factors tends to worsen the initial congestion, making it decreasingly likely that the network will recover on its own. In order to avoid this set of problems, it may be necessary to make routing decisions farther away from the congestion point. That in turn may require a method for the nodes in the congested region to report their propensity for message delay.
Naïve methods for measuring message delay collect only one timing datum per message, and then require a significant number of messages to create a reasonable approximation of the current retransmission delay. These estimates tend to be skewed with respect to time, and that skew tends to be unresponsive to the same bursts of activity that cause the initial congestion to become unmanageable.